I ran "yum update" and was presented with many many updates to be installed, kmod-nvidia the kernel, LibreOffice - lots of them maybe 50 packages.

But I was greeted at the end of these many many pages of updates, removals etc with a message

Quote:

There are unfinished transactions remaining. You might consider running yum-complete-transaction first to finish them.

so I followed this suggestion and was then presented with many, many more pages of rapidly scrolling script in the terminalending with a suggestion to try running --skip-broken to complete the updates

Is there something happening with 'YUM' that I should know about?

This has happened to me over a few days now with no indication that the command "yum update" will ever complete or that skipping broken packages or running the complete transaction command is doing anything useful

I don't mind removing SELinux (don't need it or want it) but don't know how to resolve the errors related to protected F15 libraries or 32bit Vs 64bit conflicts - this is a 64bit installation and I don't know why I have any protected 32bit stuff anyway.

I don't really feel inclined to knock my work PC on the head for the day but I would be a bit annoyed that I have to do a complete re-installation to resolve this problem.

In a lot of cases, not much, they're just put in for compatibility sake.
One way you can resolve this it to get rid of the dupes that are for the other architecture, in nearly all cases, if you're arch is x86_64 you don't use the i686 version of the package.
You could just

yum remove openldap.i686
etc
etc

for all of those packages. BUT only remove ones that don't pull out any dependencies you want

OK so I remove the packages byb running
rpm -e --nodeps packagename
there's no output but when I then run
yum update

things have gotten worse (I think)

Quote:

Downloading Packages:
Running Transaction Check
ERROR with transaction check vs depsolve:
libasound.so.2 is needed by alsa-plugins-pulseaudio-1.0.25-3.fc16.i686
libasound.so.2(ALSA_0.9) is needed by alsa-plugins-pulseaudio-1.0.25-3.fc16.i686
Please report this error in http://yum.baseurl.org/report
** Found 37 pre-existing rpmdb problem(s), 'yum check' output follows:
alsa-lib-1.0.25-1.fc16.x86_64 is a duplicate with alsa-lib-1.0.24-2.fc15.x86_64
alsa-plugins-pulseaudio-1.0.24-3.fc16.i686 has missing requires of libasound.so.2
alsa-plugins-pulseaudio-1.0.24-3.fc16.i686 has missing requires of libasound.so.2(ALSA_0.9)
alsa-utils-1.0.25-7.fc16.x86_64 is a duplicate with alsa-utils-1.0.24.1-5.fc16.x86_64
cairo-1.10.2-4.fc16.i686 has missing requires of libpng12.so.0
cairo-1.10.2-4.fc16.i686 has missing requires of libpng12.so.0(PNG12_0)
1:cups-libs-1.5.2-1.fc16.i686 has missing requires of libpng12.so.0
1:cups-libs-1.5.2-1.fc16.i686 has missing requires of libpng12.so.0(PNG12_0)
1:cups-libs-1.5.2-1.fc16.i686 has missing requires of libselinux.so.1
1:esound-libs-0.2.41-4.fc15.i686 has missing requires of libasound.so.2
1:esound-libs-0.2.41-4.fc15.i686 has missing requires of libasound.so.2(ALSA_0.9)
1:esound-libs-0.2.41-4.fc15.i686 has missing requires of libasound.so.2(ALSA_0.9.0rc4)
gd-2.0.35-13.fc16.i686 has missing requires of libpng12.so.0
gd-2.0.35-13.fc16.i686 has missing requires of libpng12.so.0(PNG12_0)
glib2-2.30.2-1.fc16.i686 has missing requires of libselinux.so.1
gstreamer-plugins-base-0.10.35-3.fc16.i686 has missing requires of libasound.so.2
gstreamer-plugins-base-0.10.35-3.fc16.i686 has missing requires of libasound.so.2(ALSA_0.9)
gstreamer-plugins-base-0.10.35-3.fc16.i686 has missing requires of libasound.so.2(ALSA_0.9.0rc4)
gvfs-1.10.1-3.fc16.x86_64 is a duplicate with gvfs-1.10.1-2.fc16.x86_64
ibus-libs-1.4.1-1.fc16.x86_64 is a duplicate with ibus-libs-1.4.0-17.fc16.x86_64
imsettings-libs-1.2.8-1.fc16.x86_64 is a duplicate with imsettings-libs-1.2.7.1-1.fc16.x86_64
krb5-libs-1.9.2-6.fc16.i686 has missing requires of libselinux.so.1
libkworkspace-4.7.4-9.fc16.x86_64 is a duplicate with libkworkspace-4.7.4-7.fc16.x86_64
2:libpng-1.2.46-2.fc16.x86_64 is a duplicate with 2:libpng-1.2.46-1.fc16.x86_64
libselinux-2.1.6-6.fc16.x86_64 is a duplicate with libselinux-2.1.6-5.fc16.x86_64
mesa-dri-drivers-7.11.2-3.fc16.i686 has missing requires of libselinux.so.1
msttcorefonts-1.3-4.noarch has missing requires of /usr/sbin/chkfontpath
openldap-2.4.26-6.fc16.x86_64 is a duplicate with openldap-2.4.26-5.fc16.x86_64
pam-1.1.5-5.fc16.i686 has missing requires of libselinux.so.1
picasa-3.0.5744-02.i386 has missing requires of libasound.so.2
systemd-37-13.fc16.x86_64 is a duplicate with systemd-37-11.fc16.x86_64
systemd-units-37-13.fc16.x86_64 is a duplicate with systemd-units-37-11.fc16.x86_64
wine-alsa-1.3.37-1.fc16.i686 has missing requires of libasound.so.2
wine-alsa-1.3.37-1.fc16.i686 has missing requires of libasound.so.2(ALSA_0.9)
wine-alsa-1.3.37-1.fc16.i686 has missing requires of libasound.so.2(ALSA_0.9.0rc4)
wine-ldap-1.3.37-1.fc16.i686 has missing requires of liblber-2.4.so.2
wine-ldap-1.3.37-1.fc16.i686 has missing requires of libldap_r-2.4.so.2
Your transaction was saved, rerun it with: yum load-transaction /tmp/yum_save_tx-2012-03-08-16-17fDcn3U.yumtx

OK so the answer to my insbaility to find the settings for desktop management and decoration in Gnome 3, my not knowing how to re-enable compiz is to ...
boot into another desktop and check the settings and make the neccesary changes there. I'm guessing that the Gnome developers are going down the Microsoft road of making it almost impossible for users to modify the desktop by hiding or removing the management tools from the default installation

I haven't managed to work out how to resolve my problem running 'yum update' and getting it to complete